a. Field of the Invention
This invention relates generally to spin-spray processing and more particularly to a method and apparatus for spin-spray processing of photoplates used for integrated circuit construction.
B. Prior Art
Spin-spray processing is old. For example, it has been used in the manufacture of semiconductor wafers. U.S. Pat. No. 3,953,265, incorporated by reference herein, shows a method and apparatus for handling fluids in semiconductor processing. Similarly, U.S. Pat. Nos. 3,041,225 and 3,489,608 both incorporated by reference herein, also show an apparatus for surface treatment of semiconductor bodies, including a structure for spin etching of semiconductors.
Previously, photomasks have not been processed by spin-spray technology for various reasons. Rather, classical photographic development techniques have been used wherein photoplates for making photomasks are transferred from one chemical bath to another. The typical time for processing a photoplate utilizing current methods and apparatus is approximately 24 minutes. During this time the photoplate is exposed to ambient air and often particles land on the photoplate which subsequently degrade the performance of it, when used to make semiconductor integrated circuits. Moreover, the amount of space occupied by a plurality of chemical baths is considerable.
Accordingly, it was our object to devise a spin-spray processing method and apparatus for photoplates wherein the amount of time required to process a photoplate could be reduced; the photoplate surface could be kept relatively free of particulate matter; the overall amount of space required to process photoplates could be dramatically reduced; and the number of processing chemicals is reduced.